Nightmare client in Georgia won't pay $2k for our landscape maintenance contract

Been doing commercial landscape maintenance for 5 years now, and this client down here in Georgia is straight up refusing to pay the last invoice for our bi-weekly mowing and edging on their office park lot. We use Toro mowers and had the contract locked in at $2k per month, everything was going smooth until they claimed we missed a few shrubs during the last trim. I sent the invoice through Jobber right after the job, but now they're ghosting me and saying it'll 'hit collections' if I push. Saw a similar rant in the Lawn Care Business Owners group about chasing deadbeat commercial clients. Sent a demand letter last week but no response, anyone dealt with this crap and got paid? FML, this is eating into my margins bad.

Man, same boat with a yard guy who stiffed me on a sod install payment last summer, had to file a small claims to get my $1.5k.